Infections, bacterial resistance, and antimicrobial stewardship: the emerging role of hospitalists

Infection Responsive Smart Delivery of Antibiotics Using Recombinant Spider Silk Nanospheres

Frequent and inappropriate usage of antibiotics has changed the natural evolution of bacteria by reducing susceptibility and increasing resistance towards antibacterial agents. New resistance mechanisms evolved in the response to host defenses and pharmaceutical interventions are threatening our ability to treat common infections, resulting in increased mortality. In the face of this rising epidemic, antibiotic drug discovery, which has long been overlooked by big pharma, is reaching a critical low. Thus, the development of an infection-responsive drug delivery system, which may mitigate multidrug resistance and preserve the lifetime of our current antibiotic arsenal, has garnered the attention of both popular science and funding agencies. The present work describes the development of a thrombin-sensitive linker embedded into a recombinant spider silk copolymer to create a nanosphere drug delivery vehicle. Recent studies have suggested that there is an increase in thrombin-like activity during Staphylococcus aureus infection; thus, drug release from this new “smart” nanosphere can be triggered in the presence of infection. A thrombin sensitive peptide (TSP) was synthesized, and the thrombin cleavage sensitivity was determined by HPLC. The results showed no cleavage of the peptide when exposed to human serum whereas the peptide was cleaved when incubated with S. aureus exudate. Subsequently, the peptide was coupled with a silk copolymer via EDC-NHS chemistry and formulated into nanospheres encapsulating antibiotic vancomycin. These nanospheres were evaluated for in vitro infection-responsive drug release and antimicrobial activity. Finally, the drug responsive nanospheres were assessed for efficacy in an in vivo septic arthritis model. Our study provides evidence that the protein conjugate was enzyme responsive and can be used to formulate targeted drug release to combat infections against multidrug-resistant bacterial strains.

Stewardship-Hospitalist Collaboration

Hospitalists represent a rapidly emerging specialty group that treats a large proportion of hospitalized patients with infections. Antimicrobial stewardship programs and hospitalist groups that focus on building a collaborative approach have been extremely successful in optimizing antimicrobial prescribing and improving patient outcomes. We discuss the tools needed to build collaborative relationships, summarize published examples of successful stewardship-hospitalist collaboration, and provide guidance on developing collaborative interventions.

Uncomplicated Urinary Tract Infection in Ambulatory Primary Care Pediatrics: Are We Using Antibiotics Appropriately?

OBJECTIVES

Antimicrobial stewardship programs target antimicrobial use within the inpatient care setting. However, most antimicrobials are prescribed at ambulatory sites. We aim to determine the appropriateness of the diagnosis and treatment of uncomplicated urinary tract infection (UTI) in children within the outpatient setting at our institution, and to evaluate the cost of antibiotic treatment in our patient cohort.

METHODS

This retrospective study was conducted by reviewing electronic records of patients aged 2 to 18 years diagnosed with uncomplicated UTI and treated with antibiotics in the outpatient setting from January 1, 2016, to April 30, 2016. Appropriate diagnosis was defined as confirmed UTI that included: pyuria (>5 white blood cells per high-power field or positive for leukocyte esterase), a positive urine culture (≥50,000 colony units/mL of a single uropathogen for a catheterized sample or ≥100,000 colony units/mL for a clean catch urine sample), and lower urinary tract symptoms. Treatment was considered appropriate if the patient was prescribed first-line antibiotic for the susceptible isolate (trimethoprim sulfamethoxazole, amoxicillinclavulanate, nitrofurantoin, and cephalexin), and if the appropriate dose was used.

RESULTS

We included 178 patients receiving a diagnosis of uncomplicated UTI and treated with antibiotics. Of these, 70% received an inappropriate diagnosis (n = 125). 58% (n= 72) of improperly diagnosed patients had polymicrobial growth in their urine cultures. Antibiotics prescribed mostly in this group were trimethoprim-sulfamethoxazole (53%, n = 66) and cephalexin (22%, n = 27). Only 30% of all included patients received an appropriate diagnosis (n = 53). Of all appropriate diagnosis patients (n = 53), 26% were treated inappropriately (n = 14) with either wide-spectrum antibiotics (n = 8) or with low calculated dose (n = 6). The estimated cost of antibiotic treatment for the inappropriate diagnosis group (n = 125) was $10,755.87.

CONCLUSION

Antimicrobial stewardship programs should target the pediatric outpatient setting and antibiograms should be developed. Education of providers about the appropriate diagnosis and treatment of uncomplicated UTI in children is essential for reducing the cost of inappropriate therapy.

The rise of hospitalists: an opportunity for infectious diseases investigators

INTRODUCTION

Despite the essential role played by infectious diseases specialists in patient care, public health, cost-containment, and biomedical research, the field has a substantially higher percentage of vacant positions than other medicine sub-specialties. While much has been written about what this disturbing trend means for patient care, comparatively little attention has been focused on the dire implications for clinical research and the development of novel anti-infective therapy. Areas covered: We examine the ways that hospitalists and infectious disease specialists might collaborate to study emerging diagnostic platforms, novel antimicrobial agents, and strengthen antimicrobial stewardship programs to improve the delivery of high-quality health care. Through the use of PubMed, the manuscript reviews existing collaborations as well as those that might develop in the years to come. Expert commentary: In this paper, we propose potential strategies to confront this emerging problem, focusing on novel collaborations with the hospitalist - the specialist in inpatient medicine - to bolster the pipeline of funding for clinical infectious diseases investigators.

Impact of interventions by an antimicrobial stewardship program team on appropriate antimicrobial therapy in patients with bacteremic urinary tract infection

BACKGROUND

Inappropriate antimicrobial therapy often leads to poor outcomes. This study aimed to evaluate the impact of an antimicrobial stewardship program (ASP) team on appropriate therapy, in patients with bacteremic urinary tract infection (UTI).

PATIENTS AND METHODS

We retrospectively reviewed the interventions by the ASP team in 807 patients with bacteremic UTI. Interventions were divided into 3 groups: group A (conventional report), group B (conventional report and written alert on the chart), and group C (conventional report and oral recommendation with/without written alert). The appropriateness of antimicrobial therapy was assessed at 2 time points, based on blood culture results.

RESULTS

The ASP team estimated that 166 and 576 patients received inappropriate antimicrobial therapy based on the results of Gram staining, and final report, respectively. Appropriate therapy after intervention was administered to 53.2% of group A, 63.5% of group B, and 89.3% of group C patients, respectively. Mortality was significantly lower in patients of de-escalation than in those with no antimicrobial changes, without prolonged hospital stay.

CONCLUSION

This study provides one plausible benchmark for appropriate antimicrobial therapy by ASP, while observer bias and survivor treatment selection bias exist, and further studies including evaluation for severity are needed.

Gram-stain-based antimicrobial selection reduces cost and overuse compared with Japanese guidelines

BACKGROUND

The Gram stain has been used as an essential tool for antimicrobial stewardship in our hospital since the 1970s. The objective of this study was to clarify the difference in the targeted therapies selected based on the Gram stain and simulated empirical therapies based on the antimicrobial guidelines used in Japan.

METHODS

A referral-hospital-based prospective descriptive study was undertaken between May 2013 and April 2014 in Okinawa, Japan. All enrolled patients were adults who had been admitted to the Division of Infectious Diseases through the emergency room with suspected bacterial infection at one of three sites: respiratory system, urinary tract, or skin and soft tissues. The study outcomes were the types and effectiveness of the antibiotics initially selected, and their total costs.

RESULTS

Two hundred eight patients were enrolled in the study. The median age was 80 years. A significantly narrower spectrum of antibiotics was selected based on the Gram stain than was selected based on the Japanese guidelines. The treatments based on the Gram stain and on the guidelines were estimated to be equally highly effective. The total cost of antimicrobials after Gram-stain testing was less than half the cost after the guidelines were followed.

CONCLUSIONS

Compared with the Japanese guidelines, the Gram stain dramatically reduced the overuse of broad-spectrum antimicrobials without affecting the effectiveness of the treatment. Drug costs were reduced by half when the Gram stain was used. The Gram stain should be included in all antimicrobial stewardship programs.

Role of the hospitalist in antimicrobial stewardship: a review of work completed and description of a multisite collaborative

BACKGROUND

Historically, antimicrobial stewardship programs have been led by infectious-disease physicians and pharmacists. With the growing presence of hospitalists in health and hospital systems, combined with their focus on quality improvement and patient safety, this emerging medical specialty has the potential to fill essential roles in antimicrobial stewardship programs.

OBJECTIVE

The goal of this article was to present the reasons hospitalists are ideally positioned to fill antimicrobial-stewardship roles, a narrative review of previously reported hospitalist-led antibiotic-stewardship projects, and a description of an ongoing multisite collaborative by the Institute for Healthcare Improvement (IHI) and the Centers for Disease Control and Prevention (CDC).

METHODS

A review of the published literature was performed, including an extensive review of the abstracts submitted to the Society of Hospital Medicine annual meetings.

RESULTS

A number of examples of hospitalists developing and leading antimicrobial-stewardship programs are described. The details of a current multisite IHI/CDC hospitalist-focused initiative are discussed in detail.

CONCLUSIONS

Hospitalists are actively involved with, and even lead, a variety of antimicrobial-stewardship programs in several different hospital systems. A large, multisite collaborative focused on hospitalist-led antimicrobial stewardship is currently in progress.